Jackscrew extension attachment



Um. M- W2% 11,511,7 4! M. J. PARKER JACKSGREW EXTENSION ATTACHMENT FiledOct; 28. 1920 WET Patented @et. 1d, 1924.

MELVIN J. PARKER, 01! QUIMBY, IOWA.

JACKSGREW EXTENSION ATTACHMENT.

Application filed October 23, 1920. Serial No. 420,125.

To all whom it may concern: Be it known that I, MELVIN J. PARKER, acitizen of the United States of America, and resident of Quimby,Cherokee County, Iowa, have invented a new and usefulJackscrewExtensio'n Attachment, of which the following is aspecification.

The object of this invention is to provide an improved extension forjack-screws which may be readily and quickly applied thereto to increasethe capacity of the j ack-screw.

A further object of this invention is to provide improved means forremovably and replaceably attaching an extension device to a jack-screw.

With these and other objects in view, my invention consists in theconstruction, arrangement and combination of elements hereinafter setforth, pointed out in my claims and illustrated by the accompanyingdrawing, in which Figures 1 and 2 are elevations, at right angles toeach other, illustrating a jackscrew with one of my improved extensionattachments applied thereto. Figure 3 is an elevation, partly insection, one member of the extension attachment being removed and thehinge and latching devices being omitted. Figure 4 is a cross-section onthe line tt'4: of Figure 3.

In the construction of the device as shown the numeral 10 designates thebase of a jackscrew, provided with a threaded vertical bore 11 receivinga screw 12 having a head 13 swivel-ed to its upper end. Immediatelybelow the head 13 a. collar 14 is fixed to the screw and is providedwith one or more diamet-rical holes 15 to receive a bar or rod (notshown) for rotating the screw in a common manner.

The extension attachment is in the nature of a jacket or sleeve formedof two mating members 16, 17 adapted to be mounted on and supplement thebase 10. The members 16, 17 when closed together preferably are of thesame diameter as the upper portion of the base and are together formedwith a vertical threaded bore 18 corresponding to and alining with thebore 11 thereof, when the attachment is in place. The base 10 preferablyis formed at its upper end with a portion 19 reduced in diameter,producing a square peripheral shoulder 20; and the members 16,17 of theattachment are formed at their lower ends with a cylindrical recessconcentric with the bore 18 and fitted to the base and form an extensionthereof. 1 As shown, the member 16 is formed with a pair of spaced,verticallyalining apertured ears 21 registering with similar ears 22 onthe member 17, through which ears passes a hinge bolt or pintle rod 23,whereby the extension members are hingedly secured together. Means isprovided for latching the members 16, 17 together at their oppositemargins, as follows: Spaced ears 24 are formed on and project from themember 17 and are formed with horizontal apertures 25, through which areloosely mounted bolts 26. On the member 16 are formed forked ears 27,having their forks in transverse alinement with the apertures of theears 2 1 and adapted toreceive the bolts 26 at times. Pivoted by pins 31to the ends of the bolts 26 are cam latching levers 28, decentered onsaid pins and having cam faces adapted to engage the outer surfaces ofthe forked ears 27, whereby the free margins of the hinged extensionmembers 16, 17 may be drawn and held closely together in the positionshown relative to the base, the lower end portions of said members 16,17 clamping and friotionally engaging the cylindrical portion 19 of theass.

In use the extension attachment may be applied and secured to the baseas shown to the end of increasing the capacity of the jack, it beingpossible for the screw 12 to move upwardly into and be supported whollyby said attachment after leaving the bore of the base. The upper end ofthe extension members preferably are formed with a reduced portion 29forming a shoulder 30, similar to and corresponding with the reducedportion and shoulder of the base, so that other extension members,identical with 16, 17, may be added thereto to further increase thecapacity of the device.

The members'are readily and quickly removed and replaced; and theextension is formed in two parts hinged together as shown and describedfor convenience in such operation, and so that they may be added withoutremoval of the screw from the base.

It is obvious that the extension attachment might be formed of a solidcylindrical bored 1 member, but with the construction shown 7 theattachment maybe added even after the 7 position relative avoiding theuse; of set screws to connect them.

. l tsho'uld noted'that when the extension'is in place it-forms acontinuation of the basemember of substantially the same diameteras-Land merging into said base;

' unfit or inconvenient for use of the attachment.

and that'no projections or enlargements are formed on thebase whichmight render it independently I claim as my invention In a j ack-screwhaving a base and a screw threaded therein, said base being formed witha reduced cylindrical upper end portion, an extension attachment formedof substantially like semi-cylindrical members, said members beingformed with relatively movable arcuate portions adapted to embrace saidreduced portion of the base, said members also being formed with reducedarcuate portions adapted conjunctively to .be embraced by superposedduplicate members.

Signed at Quimby, in the county of Cherokee and State of Iowa,

this 24th day of September, 1920.

MELVIN J. PARKER.

